A retroreflective film for signs and a method of making the same

Abstract

The application discloses a reflective film for a signboard and a manufacturing method thereof. The reflective film comprises, from top to bottom, a colored prism film, an air sealing capsule, a pressure-sensitive adhesive layer and a substrate. The colored prism film is divided into a reserved area and a color-changing area. The reserved area and the color-changing area are different in color, and the color-changing area is formed by heat-induced color change. The color-changing area is an area where a font or a pattern on the signboard is located, and the reserved area is an area where a background of the signboard is located. The specific position and size of the reserved area and the color-changing area can be set according to the content of the signboard layout. The font or the pattern on the reflective film is formed on the color-changing area by heat-induced color change, thereby eliminating the process of pasting the font or the pattern according to the layout drawing, i.e. eliminating the manual pasting step, reducing the uncontrollability of manual pasting, improving the consistency of products and improving the production efficiency.

Description

Technical Field

[0001] This invention relates to reflective film, and more particularly to a reflective film for signs and a method for manufacturing the same. Background Technology

[0002] Traffic signs play a vital role in driving safety. Improving the visibility of traffic signs at night and in adverse weather conditions such as wind, sand, snow, rain, and fog is an important way to improve road traffic safety and reduce traffic accident rates. Currently, the reflective film provided by manufacturers is only in single colors such as white and red. When making traffic signs, it is usually necessary to add other colors. For example, the publication number CN105088982A, entitled "A Traffic Sign Suitable for Backlighting Environments," uses a dark-colored base film with lettering film pasted on it to make the sign. However, making signs by pasting lettering film requires pre-cutting the reflective film with lettering before pasting it according to the layout drawings. This requires a high level of worker skill and is slow in production. Summary of the Invention

[0003] This invention addresses the shortcomings of existing technologies, such as the high skill requirements for workers and low production efficiency in the manufacture of traffic signs, by providing a new type of reflective film for traffic signs and its manufacturing method.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0005] A reflective film for signs comprises, from top to bottom, a colored prism film, an air-sealed capsule, a pressure-sensitive adhesive layer, and a substrate. The colored prism film is divided into a retention area and a color-changing area. The retention area and the color-changing area are different colors, and the color-changing area is formed by changing color after being heated.

[0006] The color-changing area is the area where the text or pattern on the sign is located, while the reserved area is the area where the background of the sign is located. The specific location and size of the reserved area and the color-changing area can be set according to the content of the sign. The text or pattern on the reflective film is formed by heat-induced color change in the color-changing area, eliminating the need for pasting the text or pattern according to the drawing, thus eliminating the manual pasting step, reducing the uncontrollability of manual pasting, and improving production efficiency while improving product consistency.

[0007] A method for manufacturing a reflective film for signs, comprising the following materials in parts by weight:

[0008]

[0009]

[0010] The thermochromic microcapsules are irreversible thermochromic microcapsules with a color-changing temperature of 90℃~110℃. The manufacturing method of the reflective film for the sign includes the following steps:

[0011] S1. Take oligomer, reactive diluent, photoinitiator, thermochromic microcapsule, leveling agent, and dispersant and mix them in proportion to form a photocurable resin;

[0012] S2. Pour the photocurable resin into a cylindrical mold with reflective microstructures and fill the reflective microstructures on the surface of the cylindrical mold. Then, use ultraviolet light to crosslink and cure the photocurable resin to form a colored prism film with reflective microstructures.

[0013] S3. An air-sealed capsule is fabricated on the underside of a colored prism film with a reflective microstructure.

[0014] S4. Take a substrate with a pressure-sensitive adhesive layer and laminate it on the underside of the air-sealed capsule to obtain a color-changing reflective product;

[0015] S5. Cut the obtained color-changing reflective product according to the shape of the sign. Then, distinguish the reserved area and the color-changing area on the colored prism film. Next, use a pressing tool with a temperature difference die to press the color-changing reflective product. The bottom surface of the temperature difference die has a low temperature zone of 20℃~30℃ and a high temperature zone of 90~110℃. The low temperature zone and the high temperature zone are on the same plane. The low temperature zone corresponds to the reserved area of ​​the color-changing reflective product, and the high temperature zone corresponds to the color-changing area of ​​the color-changing reflective product. After the color-changing area of ​​the color-changing reflective product changes color due to heat, separate the temperature difference die from the color-changing reflective product to obtain a reflective film for signs with different colors in the reserved area and the color-changing area.

[0016] Step S1 forms a cross-linkable, curable photocurable resin. Step S2 then cross-links and cures the resin to form a colored prism film with a reflective microstructure. Step S3 forms an air-sealed capsule, which, in conjunction with the colored prism film, provides retroreflective functionality. Step S4 forms a color-changing reflective product. Step S5 then creates different colored retention areas and color-changing areas on the color-changing reflective product, ultimately resulting in a reflective film that can be applied to signs. These steps eliminate the need for manual pasting, reducing the skill requirements and improving product consistency, thus lowering the defect rate and increasing production efficiency.

[0017] Preferably, in the above-described method for manufacturing reflective film for signs, a gap is provided between the high-temperature zone and the low-temperature zone of the temperature difference mold head, and the width of the gap is 0.1mm-0.3mm.

[0018] The gaps further isolate the high-temperature and low-temperature zones, thereby further improving the clarity of the boundaries between the preserved and discolored areas.

[0019] Preferably, in the above-described method for manufacturing a reflective film for signs, the gap is further filled with a heat insulation layer.

[0020] The insulation layer can better separate the high-temperature zone from the low-temperature zone, thereby further improving the clarity of the boundaries between the preserved area and the discolored area.

[0021] Preferably, in the above-described method for manufacturing a reflective film for signs, the heat insulation layer is aerogel.

[0022] Aerogel has the advantages of low thermal conductivity, high temperature resistance and long life, and has a better thermal insulation effect when used as the thermal insulation layer of the present invention.

[0023] Preferably, in the above-described method for manufacturing reflective film for signs, the temperature difference mold head is provided with a cavity, and the cavity is provided with a partitioned base. The cavity is divided into a cooling zone and a heating zone by the partitioned base. The cooling zone corresponds to the low-temperature zone, and the heating zone corresponds to the high-temperature zone. The temperature difference mold head is respectively provided with a cold circulation structure that communicates with the cooling zone and a hot circulation structure that communicates with the heating zone.

[0024] The thermal circulation structure circulates heating fluid into the heating zone, ensuring stable heating and allowing the high-temperature zone to continuously and stably heat the color-changing area of ​​the color-changing reflective product. The cold circulation structure circulates cooling water or coolant into the cooling zone, removing heat conducted from the heating zone and preventing the corresponding low-temperature zone from being affected, thus ensuring the stability of the color in the retained area. Both the thermal and cold circulation structures can utilize common inlet and outlet pipe systems, which are cost-effective and relatively easy to implement.

[0025] Preferably, in the above-described method for manufacturing reflective film for signs, the pressing time in step S5 is 5 to 6 minutes.

[0026] Selecting the pressing time within the above range can better ensure the color change effect of the color-changing area.

[0027] Preferably, in the above-described method for manufacturing a reflective film for signs, the oligomer is one of epoxy acrylate or polyurethane acrylate.

[0028] The oligomers selected from the above materials have both high curing rates and excellent chemical resistance.

[0029] Preferably, in the above-described method for manufacturing a reflective film for signs, the active diluent is at least one selected from isoborneol acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.

[0030] The above-mentioned materials are selected as reactive diluents, which have good compatibility with oligomers, can effectively reduce the viscosity of oligomers, and improve the workability of photocurable resins.

[0031] Preferably, in the above-described method for manufacturing a reflective film for signs, the photoinitiator is at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone, the leveling agent is a polyether-modified dimethyl polysiloxane copolymer, and the dispersant is a polyurethane derivative.

[0032] The photoinitiator, selected from the above materials, provides free radicals, enabling the photocurable resin to react and form cross-linked curing. The leveling agent, also selected from the above materials, improves the flowability of the photocurable resin, allowing it to more easily fill the reflective microstructures on the surface of the cylindrical mold, thereby improving production efficiency. The dispersant, selected from the above materials, enhances the stability of thermochromic microcapsules in the photocurable resin and prevents flocculation of the thermochromic microcapsules. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a reflective film for signs according to the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the temperature difference mold head and the color-changing reflective product in this invention. Figure 1 ;

[0035] Figure 3 This is a schematic diagram of the structure of the temperature difference mold head and the color-changing reflective product in this invention. Figure 2 ;

[0036] Figure 4 for Figure 3 Enlarged view of part A in the middle;

[0037] Figure 5 This is a schematic diagram of the structure of the temperature difference mold head and the color-changing reflective product in this invention. Figure 3 . Detailed Implementation

[0038] The following is in conjunction with the appendix Figure 1-5 The invention will be further described in detail with reference to specific embodiments, but these are not intended to limit the invention:

[0039] Example 1

[0040] like Figures 1 to 5 As shown, a reflective film for signs includes, from top to bottom, a colored prism film 1, an air-sealed capsule 2, a pressure-sensitive adhesive layer 3, and a substrate 4. The colored prism film 1 is divided into a retention area 51 and a color-changing area 52. The retention area 51 and the color-changing area 52 are different colors, and the color-changing area 52 is formed by changing color after being heated.

[0041] A method for manufacturing a reflective film for signs, comprising the following materials in parts by weight:

[0042]

[0043]

[0044] The thermochromic microcapsules are irreversible thermochromic microcapsules with a color-changing temperature of 90°C. The manufacturing method of the reflective film for the sign includes the following steps:

[0045] S1. Take oligomer, reactive diluent, photoinitiator, thermochromic microcapsule, leveling agent, and dispersant and mix them in proportion to form a photocurable resin;

[0046] S2. Pour the photocurable resin into a cylindrical mold with a reflective microstructure and fill the reflective microstructure on the surface of the cylindrical mold. Then, use ultraviolet light to crosslink and cure the photocurable resin to form a colored prism film 1 with a reflective microstructure.

[0047] S3. An air-sealed capsule 2 is fabricated on the underside of a colored prism film 1 with a reflective microstructure;

[0048] S4. Take the substrate 4 with the pressure-sensitive adhesive layer 3 and laminate it on the lower side of the air-sealed capsule 2 to obtain the color-changing reflective product 5.

[0049] S5. Cut the obtained color-changing reflective product 5 according to the shape of the sign, and then distinguish the retention area 51 and the color-changing area 52 on the colored prism film 1. Then, use a pressing tool with a temperature difference die head 6 to press the color-changing reflective product 5. The bottom surface of the temperature difference die head 6 forms a low temperature zone 61 with a temperature of 20°C and a high temperature zone 62 with a temperature of 90°C. The low temperature zone 61 and the high temperature zone 62 are on the same plane. The low temperature zone 61 corresponds to the retention area 51 of the color-changing reflective product 5, and the high temperature zone 62 corresponds to the color-changing area 52 of the color-changing reflective product 5. After the color-changing area 52 of the color-changing reflective product 5 changes color due to heat, the temperature difference die head 6 is separated from the color-changing reflective product 5, resulting in a reflective film for signs with different colors in the retention area 51 and the color-changing area 52.

[0050] Preferably, a gap 63 is provided between the high-temperature zone 62 and the low-temperature zone 61 of the temperature difference mold head 6, and the width of the gap 63 is 0.1 mm.

[0051] Preferably, the gap 63 is further filled with a heat insulation layer 64.

[0052] Preferably, the heat insulation layer 64 is aerogel.

[0053] Preferably, the temperature difference mold head 6 is provided with a cavity 67, and a partitioned base 68 is provided in the cavity 67. The cavity 67 is divided into a cooling zone 69 and a heating zone 610 by the partitioned base 68. The cooling zone 69 corresponds to the low temperature zone 61, and the heating zone 610 corresponds to the high temperature zone 62. The temperature difference mold head 6 is provided with a cold circulation structure 65 that communicates with the cooling zone 69 and a hot circulation structure 66 that communicates with the heating zone 610.

[0054] Preferably, in step S5, the pressing time is 5 minutes.

[0055] Preferably, the oligomer is one of epoxy acrylate or polyurethane acrylate.

[0056] Preferably, the reactive diluent is at least one of isobornyl acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.

[0057] Preferably, the photoinitiator is at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone, the leveling agent is a polyether-modified dimethyl polysiloxane copolymer, and the dispersant is a polyurethane derivative.

[0058] Example 2

[0059] like Figures 1 to 5 As shown, a reflective film for signs includes, from top to bottom, a colored prism film 1, an air-sealed capsule 2, a pressure-sensitive adhesive layer 3, and a substrate 4. The colored prism film 1 is divided into a retention area 51 and a color-changing area 52. The retention area 51 and the color-changing area 52 are different colors, and the color-changing area 52 is formed by changing color after being heated.

[0060] A method for manufacturing a reflective film for signs, comprising the following materials in parts by weight:

[0061]

[0062] The thermochromic microcapsules are irreversible thermochromic microcapsules with a color-changing temperature of 110°C. The manufacturing method of the reflective film for the sign includes the following steps:

[0063] S1. Take oligomer, reactive diluent, photoinitiator, thermochromic microcapsule, leveling agent, and dispersant and mix them in proportion to form a photocurable resin;

[0064] S2. Pour the photocurable resin into a cylindrical mold with a reflective microstructure and fill the reflective microstructure on the surface of the cylindrical mold. Then, use ultraviolet light to crosslink and cure the photocurable resin to form a colored prism film 1 with a reflective microstructure.

[0065] S3. An air-sealed capsule 2 is fabricated on the underside of a colored prism film 1 with a reflective microstructure;

[0066] S4. Take the substrate 4 with the pressure-sensitive adhesive layer 3 and laminate it on the lower side of the air-sealed capsule 2 to obtain the color-changing reflective product 5.

[0067] S5. Cut the obtained color-changing reflective product 5 according to the shape of the sign, and then distinguish the retention area 51 and the color-changing area 52 on the colored prism film 1. Then, use a pressing tool with a temperature difference die head 6 to press the color-changing reflective product 5. The bottom surface of the temperature difference die head 6 forms a low temperature zone 61 with a temperature of 30°C and a high temperature zone 62 with a temperature of 110°C. The low temperature zone 61 and the high temperature zone 62 are on the same plane. The low temperature zone 61 corresponds to the retention area 51 of the color-changing reflective product 5, and the high temperature zone 62 corresponds to the color-changing area 52 of the color-changing reflective product 5. After the color-changing area 52 of the color-changing reflective product 5 changes color due to heat, the temperature difference die head 6 is separated from the color-changing reflective product 5, resulting in a reflective film for signs with different colors in the retention area 51 and the color-changing area 52.

[0068] Preferably, a gap 63 is provided between the high-temperature zone 62 and the low-temperature zone 61 of the temperature difference mold head 6, and the width of the gap 63 is 0.3mm.

[0069] Preferably, the gap 63 is further filled with a heat insulation layer 64.

[0070] Preferably, the heat insulation layer 64 is aerogel.

[0071] Preferably, the temperature difference mold head 6 is provided with a cavity 67, and a partitioned base 68 is provided in the cavity 67. The cavity 67 is divided into a cooling zone 69 and a heating zone 610 by the partitioned base 68. The cooling zone 69 corresponds to the low temperature zone 61, and the heating zone 610 corresponds to the high temperature zone 62. The temperature difference mold head 6 is provided with a cold circulation structure 65 that communicates with the cooling zone 69 and a hot circulation structure 66 that communicates with the heating zone 610.

[0072] Preferably, in step S5, the pressing time is 6 minutes.

[0073] Preferably, the oligomer is one of epoxy acrylate or polyurethane acrylate.

[0074] Preferably, the reactive diluent is at least one of isobornyl acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.

[0075] Preferably, the photoinitiator is at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone, the leveling agent is a polyether-modified dimethyl polysiloxane copolymer, and the dispersant is a polyurethane derivative.

[0076] Example 3

[0077] like Figures 1 to 5 As shown, a reflective film for signs includes, from top to bottom, a colored prism film 1, an air-sealed capsule 2, a pressure-sensitive adhesive layer 3, and a substrate 4. The colored prism film 1 is divided into a retention area 51 and a color-changing area 52. The retention area 51 and the color-changing area 52 are different colors, and the color-changing area 52 is formed by changing color after being heated.

[0078] A method for manufacturing a reflective film for signs, comprising the following materials in parts by weight:

[0079]

[0080] The thermochromic microcapsules are irreversible thermochromic microcapsules with a color-changing temperature of 100°C. The manufacturing method of the reflective film for the sign includes the following steps:

[0081] S1. Take oligomer, reactive diluent, photoinitiator, thermochromic microcapsule, leveling agent, and dispersant and mix them in proportion to form a photocurable resin;

[0082] S2. Pour the photocurable resin into a cylindrical mold with a reflective microstructure and fill the reflective microstructure on the surface of the cylindrical mold. Then, use ultraviolet light to crosslink and cure the photocurable resin to form a colored prism film 1 with a reflective microstructure.

[0083] S3. An air-sealed capsule 2 is fabricated on the underside of a colored prism film 1 with a reflective microstructure;

[0084] S4. Take the substrate 4 with the pressure-sensitive adhesive layer 3 and laminate it on the lower side of the air-sealed capsule 2 to obtain the color-changing reflective product 5.

[0085] S5. Cut the obtained color-changing reflective product 5 according to the shape of the sign, and then distinguish the retention area 51 and the color-changing area 52 on the colored prism film 1. Then, use a pressing tool with a temperature difference die head 6 to press the color-changing reflective product 5. The bottom surface of the temperature difference die head 6 forms a low temperature zone 61 with a temperature of 25°C and a high temperature zone 62 with a temperature of 100°C. The low temperature zone 61 and the high temperature zone 62 are on the same plane. The low temperature zone 61 corresponds to the retention area 51 of the color-changing reflective product 5, and the high temperature zone 62 corresponds to the color-changing area 52 of the color-changing reflective product 5. After the color-changing area 52 of the color-changing reflective product 5 changes color due to heat, the temperature difference die head 6 is separated from the color-changing reflective product 5, resulting in a reflective film for signs with different colors in the retention area 51 and the color-changing area 52.

[0086] Preferably, a gap 63 is provided between the high-temperature zone 62 and the low-temperature zone 61 of the temperature difference mold head 6, and the width of the gap 63 is 0.2 mm.

[0087] Preferably, the gap 63 is further filled with a heat insulation layer 64.

[0088] Preferably, the heat insulation layer 64 is aerogel.

[0089] Preferably, the temperature difference mold head 6 is provided with a cavity 67, and a partitioned base 68 is provided in the cavity 67. The cavity 67 is divided into a cooling zone 69 and a heating zone 610 by the partitioned base 68. The cooling zone 69 corresponds to the low temperature zone 61, and the heating zone 610 corresponds to the high temperature zone 62. The temperature difference mold head 6 is provided with a cold circulation structure 65 that communicates with the cooling zone 69 and a hot circulation structure 66 that communicates with the heating zone 610.

[0090] Preferably, in step S5, the pressing time is 5.5 minutes.

[0091] Preferably, the oligomer is one of epoxy acrylate or polyurethane acrylate.

[0092] Preferably, the reactive diluent is at least one of isobornyl acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.

[0093] Preferably, the photoinitiator is at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone, the leveling agent is a polyether-modified dimethyl polysiloxane copolymer, and the dispersant is a polyurethane derivative.

[0094] In summary, the above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included within the scope of the present invention.

Claims

1. A reflective film for signage, comprising, from top to bottom, a colored prism film (1), an air-sealed capsule (2), a pressure-sensitive adhesive layer (3), and a substrate (4), characterized in that: The colored prism film (1) is divided into a retention area (51) and a color-changing area (52). The retention area (51) and the color-changing area (52) are different colors, and the color-changing area (52) is formed by changing color after being heated. The manufacturing method includes the following materials in parts by weight: 20-80 parts oligomer 10-50 parts reactive diluent 1-5 parts photoinitiator 5-10 parts of thermochromic microcapsules 1-3 parts leveling agent 1-3 parts dispersant The thermochromic microcapsules are irreversible thermochromic microcapsules with a color-changing temperature of 90℃~110℃, and include the following steps: S1. Take oligomer, reactive diluent, photoinitiator, thermochromic microcapsule, leveling agent, and dispersant and mix them in proportion to form a photocurable resin; S2. The photocurable resin is poured into a cylindrical mold with a reflective microstructure and the reflective microstructure is filled on the surface of the cylindrical mold. Then, the photocurable resin is cross-linked and cured with ultraviolet light to form a colored prism film with a reflective microstructure (1). S3. An air-sealed capsule (2) is made on the underside of a colored prism film (1) with a reflective microstructure. S4. Take a substrate (4) with pressure-sensitive adhesive layer (3) and laminate it on the underside of the air-sealed capsule (2) to obtain a color-changing reflective product (5). S5. Cut the obtained color-changing reflective product (5) according to the shape of the sign, and then distinguish the retention area (51) and the color-changing area (52) on the colored prism film (1). Then, use a pressing tool with a temperature difference die (6) to press the color-changing reflective product (5). The bottom surface of the temperature difference die (6) forms a low temperature zone (61) with a temperature of 20℃~30℃ and a high temperature zone (62) with a temperature of 90~110℃. 1) The high temperature zone (62) is on the same plane. The low temperature zone (61) corresponds to the reserved area (51) of the color-changing reflective product (5). The high temperature zone (62) corresponds to the color-changing area (52) of the color-changing reflective product (5). After the color-changing area (52) of the color-changing reflective product (5) changes color due to heat, the temperature difference mold head (6) is separated from the color-changing reflective product (5) to obtain a reflective film for signs with different colors of the reserved area (51) and the color-changing area (52).

2. The reflective film for signs according to claim 1, characterized in that: A gap (63) is provided between the high temperature zone (62) and the low temperature zone (61) of the temperature difference mold (6), and the width of the gap (63) is 0.1mm-0.3mm.

3. The reflective film for signs according to claim 2, characterized in that: The gap (63) is also filled with a heat insulation layer (64).

4. The reflective film for signs according to claim 3, characterized in that: The heat insulation layer (64) is aerogel.

5. The reflective film for signs according to claim 1, characterized in that: The temperature difference mold (6) is provided with a cavity (67), and a partition base (68) is provided in the cavity (67). The cavity (67) is divided into a cooling zone (69) and a heating zone (610) by the partition base (68). The cooling zone (69) corresponds to the low temperature zone (61), and the heating zone (610) corresponds to the high temperature zone (62). The temperature difference mold (6) is provided with a cold circulation structure (65) that communicates with the cooling zone (69) and a hot circulation structure (66) that communicates with the heating zone (610).

6. The reflective film for signs according to claim 1, characterized in that: In step S5, the pressing time is 5 to 6 minutes.

7. The reflective film for signs according to claim 1, characterized in that: The oligomer is one of epoxy acrylate or polyurethane acrylate.

8. The reflective film for signs according to claim 1, characterized in that: The reactive diluent is at least one of isobornyl acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.

9. The reflective film for signs according to claim 1, characterized in that: The photoinitiator is at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone, the leveling agent is a polyether-modified dimethyl polysiloxane copolymer, and the dispersant is a polyurethane derivative.

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